The present invention relates generally to a process for removing metallic impurities from alkali metals, and more particularly to an extraction process utilizing molten lithium for extracting impurities from other alkali metals.
Alkali metals are frequently used in the chemical industry as reactants in various processes including the synthesis of drugs and the production of organic compounds. Alkali metals in Group IA of the periodic system consist of lithium, sodium, potassium, rubidium, cesium, and francium. The purity of the particular alkali metal used in many of the chemical processes is often critical to the success of the process since the presence of metallic impurities may significantly detract from the process and/or also contaminate the end product with an undesirable concentration of metallic impurities. These metallic impurities include calcium compounds and magnesium, iron, or titanium. The purification of alkali metals for removing the above and other metallic impurities from the alkali metals include well known distillation, recrystallization and electrolysis processes. These processes have been found to be relatively expensive and, in some instances, fail to provide the alkali metal with the desired purity.